如何对具有多对多关系的两个MySQL表中的列求和

我需要检索每个学生的值，如下所示

student full name | costs | discounts | net Value | payments | remaining

当我尝试

SELECT 
    concat_ws(' ',students.firstname,students.secondname,students.thirdname,students.forthname,students.lastname),
        students.birthdate,
        sum(costs.value),
        sum(discounts.value),
        sum(costs.value)-sum(discounts.value),
        sum(payments.amount),
        sum(costs.value)-sum(discounts.value)-sum(payments.amount)     

FROM students
JOIN coststudents 
       ON  coststudents.student_id = students.student_id 
 JOIN costs  
    ON  costs.cost_id = coststudents.cost_id
JOIN discountstudent 
       ON  discountstudent.student_id = students.student_id 
JOIN discounts  
    ON  discounts.id = discountstudent.id
JOIN payments 
       ON  payments.student_id = students.student_id 

它只给出一行，与查询不对应。

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请提供帮助。

将GROUP BY students.student\u id放在代码末尾

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编辑：改为使用左连接。

否，它获取的数据与我想要获取的数据不符，计算结果完全错误！